html, body{
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

.container{
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
a{
    text-decoration: none;
    position: absolute;
    left: 50%;
    transform: translate(-50%,-50%);
    font-size: 2rem;
    line-height: 5rem;
    background: linear-gradient(90deg,#03a9f4,#f441a5,#ffeb3b,#03a9f3);
    background-size: 400%;
    width: 18rem;
    height: 5rem;
    color: #ffffff;
    text-align: center;
    border-radius:2.5rem;
    z-index: 1;
}
a::before{
    content: "";
    position: absolute;
    left: -5px;
    right: -5px;
    top: -5px;
    bottom: -5px;
    background: linear-gradient(90deg,#03a9f4,#f441a5,#ffeb3b,#03a9f3);
    background-size: 400%;
    border-radius: 3.2rem;
    filter: blur(1.25rem);
    z-index: -1;
}
a:hover::before{
    animation: sun 8s infinite;
}
a:hover{
    animation: sun 8s infinite;
}
@keyframes sun {
    100%{
        background-position: -400% 0;
    }
}
#title{
    top: 2%;
    width: 100%;
    position: fixed;
    font-family: 华文楷体, serif;
    text-align: center;
    font-size: 3rem;
    font-weight: bold;
    letter-spacing: 1rem;
    color: #fff5f0;
}






